Critical Stop sound every hour!

[WithoutMotive]

While I'm posting I might as well throw this one out there.

For a while now, every single computer on our Curriculum network makes the Critical Stop sound about 5 times in quick succession on the hour, every hour.

I've checked several times and there's no programs running every hour.

I've just no idea.

 

Any suggestions?

[Domino]

may I be the first to say MWHAHAHAHAHA

 

thats amazing!

 

have you run hijackthis on any of those and seen if there's something infected them?

[computer_expert]

Checked scheduled tasks to make sure nothing has been set to run hourly?

[DMcCoy]

NOD32?

[sparkeh]

Ok how about this: run procmon just before the hour and see what is accessing beep.wav (i think that's the critical stop sound)